1. Field of the Invention
The present invention relates to an ink jet recording apparatus having an ink jet head for use in the recording or printing (hereinafter referred to as “recording”) of characters, symbols or images (hereinafter typically referred to as “image”) by discharging the ink or functional liquid (hereinafter typically referred to as “ink”) onto the recording carrier such as the paper, plastic sheet, cloth, article and so on (hereinafter typically referred to as “paper”), or an ink jet pen containing an ink reservoir for reserving the ink to be supplied to the ink jet head. This invention also relates to an operation method for the ink jet apparatus.
By the ink jet pen as herein used is meant encompassing both the cartridge form having an ink jet head and an ink reservoir integrally provided and the form having them separately provided to be detachable. This ink jet pen can be freely attached to or detached from mounting means such as a carriage on the main unit of the apparatus. Also, by the ink jet apparatus as herein used is meant encompassing a variety of forms including those integrally or separately provided as the output terminal for the information processing equipment such as a word processor or a computer, a copying machine combined with an information reader, a facsimile apparatus having the information transmission or reception feature, and a machine for the textile printing onto the cloth.
2. Related Background Art
In the ink jet recording apparatus, when the apparatus is not used for a long time, the water content or other volatile components within the nozzles (hereinafter also referred to as “discharge orifices”) may vaporize to cause the viscosity of the ink to increase or bubbles to mix into the nozzles or ink flow passageways, thereby impeding the ink from being excellently discharged. In order to recover such ink condition to original excellent condition for the ink discharge, the ink jet recording apparatus is often provided with some recovery means. One example of such recovery means may include a suction mechanism for sucking the ink from the nozzles when a cap covers the nozzles, and supplying the new ink from an ink tank to a head. Typical elements constituting such suction mechanism include a cylinder pump for generating pressure changes by the use of the relative movement between the cylinder and the piston, and a tube pump for generating pressure changes by stroking the tube.
In such ink jet recording apparatus, it was apprehended that if the ink dries inside of a suction mechanism, that is, inside of a cap, a pump, an ink suction passageway leading from the cap to the pump, or a waste ink flow passageway leading from the pump to a waste ink reservoir, the dried ink may cause an inconvenience of blocking the flow of the ink. For example, it was apprehended that if the ink solidifies within the pump, the pump may be possibly stopped. Or it was apprehended that the ink solidifies inside the waste ink flow passageway and is impeded from flowing, though the ink is essentially directed into the waste ink reservoir, so that the ink is reversely flowed to the head side to make worse the discharge characteristics, thereby having adverse effect on the recording quality, or the ink will overflow from unexpected portion into the apparatus to contaminate the apparatus inside or have detrimental effect on the electric circuit within the apparatus.
Such problems also exist on the side of the ink jet head. For example, a typical example of the ink jet pen as previously described includes a form in which an ink jet head and an ink reservoir for reserving the ink to be supplied to the head are integrated together detachably. The ink jet head is provided with discharge orifices for discharging the ink, and also electrothermal converters to generate the heat energy, for example, as the energy used to discharge the ink from the discharge orifices. The ink reservoir mostly contains a porous absorbing member for reserving the ink. The ink supply passageway for communicating the ink jet head to the ink reservoir is commonly provided with a filter to trap the foreign matter such as dirt in the ink.
In the use of such ink jet pen, when the ink reservoir was not attached to the ink jet head for a long time, it occurred that ink components vaporized from the filter portion of ink supply passageway or discharge orifices to cause the ink to solidify and be fixed to the wall surface of ink passageway. There was a problem that once such ink fixing occurs, the supply of the ink is impeded by fixed ink and the discharge of the ink becomes bad even if the ink reservoir is attached again to the ink jet head.
The above-mentioned technical problem is more remarkable in the case of using the waterproof ink which becomes water insoluble after drying. The waterproof ink which becomes water insoluble after drying can meet a recent technical demand of improving the waterproofness of recorded image, but on the other hand, has brought about a new technical problem that the ink is more likely to fix in the interior of the apparatus. That is, this is a technical problem that such waterproof ink is liable to fixing in the interior of the recovery mechanism or the ink passageways of the ink jet head.